Email systems are commonly comprised of a large number of mailbox servers, each containing a large number of user mailboxes. Each user mailbox typically has a size quota limiting the number and/or size of the emails that can be stored in the user mailbox. Archiving systems are commonly used to periodically transfer email messages from user mailboxes to archived storage in order to keep the size of the user mailboxes below the size quota.
Archiving of emails is commonly initiated at set intervals, such as daily, weekly, or monthly. Older messages are typically archived before newer messages. Email users often need to spend time managing their user mailboxes in order to prevent email messages they need from being archived.